No MAP pressure reading

mattwynn · Post by **mattwynn** » Sun Sep 13, 2009 3:54 pm

Hi
we have been running v4 for a while now with no issues, however came yesterday to add a second map, when on testing realised that there was no pressure reading. i'm assuming that that it has been running in "2D" mode. however any ideas why it would stop working ( i sure it was working originally!) and how to test/ fix it.
regards
Matt

NITROPIXIE · Post by **NITROPIXIE** » Sun Sep 13, 2009 7:27 pm

Can you confirm that your MAP sensor is connected to the Manifold is the first place i would start.

Then check the MAP sensor is working correctly by putting some hose on it and sucking on it while having power to the megajolt unit and it is plugged into the computer.

If that doesn't work then we will need to check there is a voltage getting to the Sensor on the board and it is creating an output signal with a change of vacuum. Do you have access to a voltmeter?? Try the first two steps and i will findout what pins you need to test if that doesn't work.

Where abouts are you located???

mattwynn · Post by **mattwynn** » Tue Sep 15, 2009 5:22 pm

HI checked the pins on the map sensor as per the instructions and can confirm that there is 5v between pins 4 and 5. so whats next? currently reading no pressure at all when powered up.
regards
Matt

NITROPIXIE · Post by **NITROPIXIE** » Tue Sep 15, 2009 8:00 pm

Try applying power just to the megajolt unit. Confirm 5v between pins 4 and 5 again. Place a voltmeter across ground and pin 6. Then place a tube onto the MAP sensor. You should then be able to vary the voltage between pin 6 and ground by sucking on the pipe. This will eliminate a fault with MAP sensor

Post by **brentp** » Tue Sep 15, 2009 8:35 pm

What value does the software show when connected to the controller? (load gauge in the software)

mattwynn · Post by **mattwynn** » Tue Sep 15, 2009 9:22 pm

Thanks NITROPIXIE i'll try that tomorrow in the light.
Thanks for getting back to me too Brent, the software shows 0kPA when connected and the unit fully powered up. Everything seems to working fine including switching maps on the fly.
thanks for both your help in this
I'll post readings tomorrow
regards
Matt

Post by **brentp** » Tue Sep 15, 2009 10:17 pm

Matt,

When connected to a running engine does the RPM gauge show a reading? Can you read the current ignition config. from the controller?

I just want to ensure the controller is actually communicating with the software...

mattwynn · Post by **mattwynn** » Wed Sep 16, 2009 7:42 am

Hi Brent
yes when the engine is running the software reads the RPM and you can see the cell move ( advance changes) along a single line depending on the RPM, i can also read and write different MAPs to the unit as well as see them change configure when i flip the "MAP" swtich.
regards
Matt

mattwynn · Post by **mattwynn** » Wed Sep 16, 2009 1:57 pm

Next installment!
I'm showing approx 1.5 v between pin 6 and ground dropping down to approx 0.5 v by sucking on the pipe. no increase when blow! also getting the same drop between ground pin 5 and R4 but no reading at all between ground andthe far side of C8! and nothing at R1.
does this make sense to anyone?
thanks
Matt